Here is the article peter did on stocking up the forend:
http://photos.imageevent.com/badgerd...0correctly.pdf
Here is another:
Milsurps Knowledge Library - Worn draws in your No1, 4 or 5 fore-end .... (by Peter Laidler)
There are numerous thread covering this in "The Restorers Corner":
Military Surplus Collectors Forums
Have a look there and see what has been put up. It is a very difficult little bit of timber fitting to get it right.